S/Sheet improvement

I am the ticket secretary for a local theatre goup and have devised an excel spreadsheet to make the booking and ticketing that much easier.

My spreadsheet has a daily seating plan which will record the type and price of each 'taken' seat. It also shows the totals of each type of ticket, how much ticket money has been received, how much is due and the percentage of seats sold. All this information feeds into a 'stats' sheet which will give relative info or the production run.

It is necessary to record customer details, and to this end I have created another tab upon which I manually enter the relevant customer detail along with ticket numbers and payment details etc.

I think my system, although helpful, can be improved by reversing the process that I currently use.

I think I should create 'a customer card' which, along with the usual essential info, would have fields to enter the performance day/date, the type of ticket (Full, Concession etc), the price of the ticket and the allocated seat numbers.
The process would then require those ticketing details to be transferred to relevant seat on my current seating plan. The present system would then take over to produce the 'Stats' info.

I'm thinking that there should be a drop down list of available seats for any given performance which would then reflect any 'taken' ticket when the list is used again

Long winded set up (sorry) but this is where help and advise is needed:
What formula would link a ticket type for a particular performance to the relevant established seating plan?
How do I create a dropdown list and how would I reflect 'availabilty only'?

Is this idea at all possible?

I have attached my Seating spreadsheet to show my work thus far.

Bobbybee